Doctor mechanism for paper machines



Feb. 21, 1950 E. LJUNGQUIST 2,498,214

DOCTOR MECHANISM FOR PAPER MACHINES Filed June 20, 1946 2 Sheets-Sheet l so BIT-25 a"! as 9 ,4 [3O 2| l I 46 25 u 7 7 2! as 30 as o W \9 4 36 as u r 5d 25 4 1 40" 49 5| 47 o :Lfi

46 as 52 9 H -4 A? 36 I as L5 3 L INVENTOR 30 Ernst R. L 'ung uist v v gym 41/4/20 W 4 ATTORNEY 21. 1950 E: R. LJUNGOUIST 2,498,214

DQGTOR- MECHANISM FdR PAPER MACHINES Filed June 20, 1946 2 Sheets-Sheet 2 l NV ElNT-OR 9 Ernst RLun' uist 2, BY M4 %%dn ATTORNEY Patented Feb. 21, 1950 v DOCTOR MECHANISM FOR PAPER MACHINES Ernst R. Ljungquist, Worcester, Mass assiznor to Lodding Engineering Corporation, Worcester, Mass., a corporation of Massachusetts Application June 20, 1946, Serial No. 878,003

1 Claim. l

The present invention relates to paper making machines, and more particularly to those devices known as doctors or scrapers which are employed for the purpose of cleaning the surfaces of paper making machine cylinder rolls.

The primary object of the present invention is to provide a cylinder roll doctor blade with simple, but yet highly efficient, means for moving said blade back and forth in a direction parallel to the axis of the calender roll being doctored.

A further object of the present invention is to provide a doctor blade vibrating mechanism of a character such that it may readily be attached to any of the usual type of calendering machines with little or no modifications required in either the calendering machine or in the vibrating mechanism.

With the above and other objectives in view, as will hereinafter appear, the invention comprises the devices, combinations, and arrangements of parts hereinafter set forth and illustrated in the accompanying drawings of a preferred embodiment of the invention, from which the several features of the invention and the advantages attained thereby will be readily understood by those skilled in the art.

In the accompanying drawings Fig. 1 represents a vertical section of a calendering machine in which the present invention is embodied.

Fig. 2 represents a right side view of the calendering machine illustrated in Fig. 1.

Fig. 3 is a sectional view takensubstantially along line 3-3 of Fig. 2.

Fig. 4 is a sectional view taken substantially along line 4-4 of Fig. 3.

Referring particularly to Figs. 1 and 2, the calendering machine therein disclosed comprises a machine base portion I having spaced frame members II and I2 projecting upwardly therefrom. Each of the frame members II and [2 have arms I3 and It projecting therefrom. Mounted on the calendering machine in the usual manner are calendering rolls designated generally by the numeral IS. A paper web It traverses the machine in a direction indicated by the arrows in Fig. 1, all in the usual manner.

Arranged substantially on opposite sides of the consecutive rolls l5 are doctor blades l1, each of which is suitably mounted in a blade holder l8. Each of these blade holders l8 comprises a substantially L-shaped member having welded, or otherwise suitably secured, to the opposite end portions thereof trunnion members in the form of relatively short cylindrical shafts II and 20. Each of the oppositely opposed trimnion members 19 and 2., carried by the member II, is rotatably journaled in a respective bracket member 2| and 22. As may be seen from Figs. 1 and 2, bracket members 2| and 22 are mounted in guide ways 23 and 24 respectively which are carried on the opposed calender arms I! and I4. As may be understood from the above description, a turning movement of each holder it about its common pivotal axis, defined by the trunnions, serves to bring the blades l1 into engagement with the rotating surface of its associated calender roll ll.

A bolt 25 provides for the vertical adjustment of each of the bracket members 2| and 22 along the respective guide ways 23 and 24. Thus, each of the doctors l1 may be brought into proper adjustment with the rotating surface of its associated calender roll.

The present invention utilizes a motor drive mechanism in order to vibrate the doctor blades back and forth along the calender roll surface in a direction parallel to the axis of said roll. Referring more specifically to Figs. 3 and 4, each of the bracket members 2| is provided with a vertical slot 26 for guiding a block 21 which is embraced therein. The lower portion of each of the blocks 21 is provided with rack teeth 28.. In proper mesh with each rack is a pinion 29 carried by a stub-shaft 30 which is journaled in opposed side walls of the bracket member 2|. Referring to Fig. 4, each trunnion shaft I0 is provided with a reduced portion 3| which is rotatably joumaled within an aperture 32 provided in the block 21 and has provided in-the distal end thereof a pin 32. The block 21 is thus embraced between the pin 33 and a shoulder portion 34 of the trunnion. As may be seen in Fig. 2, the bracket member 22 merely provides an aperture 24 into which a reduced end portion 25 of .the trunnion is rotatably and slidably journaled. Thus, it may be understood that an oscillatory motion imparted to each pinion 2. will be effective to shift each doctor blade back and double pulley 36, depending on the particular location of the bracket member. Referring to Fig. 1, it may be seen that the top stub-shaft carried by arm It is connected to a. mid stubshaft by means of a belt or chain 21. The mid can;

stub-shaft is in turn similarly connected to a lower stub-shaft by means oi a similar belt ll.

' electric motor 39, or other suitable driving means, which is connected by means of a belt 4| to a pulley 4|. Pulley 4i is carried on the outboard end oi. a shaft 42 extending into a frame 43 therein to be connected to a counter shaft 44 by gears or other suitable means. The counter shaft 44, also journaied in the frame 43, carries a driving disk 45 on one end portion thereof. Eccentrically mounted upon the drive disk 45 is a pin 46 embraced by the upper end of a link member 41 whose lower end is pivotally connected to the free end of an oscillatory crank 48. This crank 48 is carried by and secured to a substantially horizontally disposed shaft 49 which is rockably journaled in spaced bearings 50 and ii formed on the machine base i0. Also mounted upon the shaft 49 is a pulley 52 over which is trained a belt 53 which is also trained over the double pulley 36. A second pulley 53 is carried by the shaft 49 and is similarly connected to a double pulley 36 by means of a belt 54. Thus it may be understood that continuous rotation of the pulley 4| will be effective to oscillate the crank 48 thereby to impart an oscillatory endwise motion to each of the trunnions 19. Such oscillatory motions of each of the trunnions l9 will impart the desired back and forth or vibratory motions to each of the doctor blades II. It will be obvious that the amplitude of vibratory motion imparted to the doctor blades I! may readily be varied by merely changing the amount of eccentricity of the pin 46, the length of the crank 48, or by suitably altering the diameters of the pulleys 52 and 53.

From the above description it is to be understood that the present invention comprises a most novel type of doctoring actuating mechanism which, because of itsinherent compactness, may be readily applied to most any type of calendering machine. Furthermore, the present invention comprises a doctor blade vibratory mechanism which, because of its simple but yet unique design, permits of inexpensive manuiacture thereof.

I claim:

In a doctor operating mechanism for a paper making machine having spaced stationary frame members and a plurality of rolls stacked therebetween, a doctor bladedisposed adjacent each oi said rolls, a carrier for each 01' said doctor blades, trunnion members secured upon and extending beyond the opposite end portions 01' each of said carriers, means carried on said frame members for rotatably and slidably supporting one trunnion of each of said carriers, apertured block members each rotatably receiving therein a respective one of the other of said trunnion members, means to prevent relative endwise movement between each of said blocks and its associated trunnion member, and bracket members carried by said frame members for slidably supporting each oi said blocks; the combination therewith of means for imparting back and forth endwise movements to said block carriers, said means comprising a rack mounted upon each of said blocks and disposed lengthwise of its associated carrier, a stub-shaft carried by each oi said bracket members, each stub-shaft being disposed adjacent and substantially at right angles to its associated trunnion, a pinion carried upon each of said stub-shafts and meshing with a respective one of said racks, a pulley mounted upon each stub-shaft, a single motor-actuated crank member, and meam connecting each of said pulleys with said crank member thereby to oscillate all of said doctor blades back and forth in unison.

ERNST R. LJUNGQUIST.

REFERENCES CITED The following references are of record in the tile of this patent:

UNITED STATES PATENTS I Date 

